fix: sing-based listener panic

common/net/packet.go

@@ -15,20 +15,24 @@ var NewDeadlinePacketConn = deadline.NewPacketConn
 var NewDeadlineEnhancePacketConn = deadline.NewEnhancePacketConn
 
 type threadSafePacketConn struct {
-	net.PacketConn
+	EnhancePacketConn
 	access sync.Mutex
 }
 
 func (c *threadSafePacketConn) WriteTo(b []byte, addr net.Addr) (int, error) {
 	c.access.Lock()
 	defer c.access.Unlock()
-	return c.PacketConn.WriteTo(b, addr)
+	return c.EnhancePacketConn.WriteTo(b, addr)
 }
 
 func (c *threadSafePacketConn) Upstream() any {
-	return c.PacketConn
+	return c.EnhancePacketConn
+}
+
+func (c *threadSafePacketConn) ReaderReplaceable() bool {
+	return true
 }
 
 func NewThreadSafePacketConn(pc net.PacketConn) net.PacketConn {
-	return &threadSafePacketConn{PacketConn: pc}
+	return &threadSafePacketConn{EnhancePacketConn: NewEnhancePacketConn(pc)}
 }